murder-unpack

Reverse-engineer exported Murder Engine games back into editor-openable projects. Extracts sprites, dialogues, world data, and more.

Features

• Project recovery — Reconstruct a Murder Engine editor project from an exported game
• C# decompilation — Full source recovery from managed single-file bundles via bundled per-type decompiler (ilspycmd fallback)
• C# stub generation — Fallback: auto-generate typed C# classes from packed JSON data (NativeAOT games)
• Per-game fixes — Auto-detected decompiler artifact fixes with extensible registry
• Asset extraction — Unpack .gz data files into individual JSON assets
• Sprite extraction — Extract individual sprites from texture atlas sheets as PNG
• Dialogue export — Reconstruct .gum scripts and export to markdown
• Localization export — Export localization CSV files matching Murder's editor format
• Engine version detection — Per-game lookup for known games, fingerprint detection for unknown games
• macOS .app support — All commands accept .app bundle paths directly
• Binary analysis — Detect .NET deployment format (NativeAOT, single-file, self-contained)
• Repacking — Repack modified assets back into .gz format
• Plugin system — Extend with drop-in .py files or pip-installable packages

Quick Start

Requirements

• Python 3.11+
• uv (recommended) or pip
• Git (for engine cloning)
• .NET SDK matching the game's engine version (net7.0 or net8.0; for building recovered projects and the bundled decompiler)

Install

# With uv (recommended)
uv tool install murder-unpack

# Or from source
git clone https://github.com/yuna0x0/murder-unpack.git
cd murder-unpack
uv sync

Usage

# Show game info and detected engine version
murder-unpack info "path/to/game"

# Extract all data, sprites, dialogues, and localization
murder-unpack extract-all "path/to/game" output/

# Recover into a full editor project
murder-unpack recover "path/to/game" recovered/

# List assets with optional filters
murder-unpack list-assets "path/to/game" --type WorldAsset

Commands

Recovery Options

murder-unpack recover "path/to/game" recovered/ \
    --engine-version rel/11.0 \    # Override auto-detected version (branch/tag/commit)
    --engine-repo https://...  \   # Use a fork or custom engine repo
    --game-name MyGame \           # Project name (auto-detected)
    --engine-path /path/to/murder  # Use existing engine clone
    --skip-engine \                # Don't clone engine
    --no-stubs \                   # Skip C# stub/decompilation
    --decompile-timeout 1200       # Decompilation timeout (default: 600)
    --game-fix neverway            # Per-game fix (auto-detected, 'none' to skip)

Per-Game Fixes

Decompiled code sometimes has game-specific issues that can't be fixed generically (lost tuple element names, readonly field assignments, duplicate local functions). The fix registry auto-detects the game and applies known fixes.

Detection uses: assembly name, game namespace, Steam App ID, or game_config $type. Each game fix can also provide the exact engine commit for accurate recovery.

Adding a fix for a new game

Create murder_unpack/fixes/my_game.py:

from murder_unpack.fixes import GameFix, Replacement

FIX = GameFix(
    id="my-game",
    name="My Game",
    assembly_names=["MyGame"],
    steam_app_ids=["123456"],
    engine_version="abc123...",  # exact engine commit (optional)
    replacements=[
        Replacement(
            file_glob="**/SomeFile.cs",
            old="broken code",
            new="fixed code",
            description="CS1234: description of the issue",
        ),
    ],
)

Register in murder_unpack/fixes/__init__.py:

def _load_builtin_fixes() -> None:
    from murder_unpack.fixes import my_game
    _registry.register(my_game.FIX)

Or register via plugin:

def register(registry):
    from murder_unpack.fixes import get_registry
    get_registry().register(my_fix)

Plugin System

Plugins extend murder-unpack with custom asset handlers, extractors, commands, and hooks.

Drop-in plugins — Place .py files in ~/.murder-unpack/plugins/ or ./plugins/:

# plugins/my_plugin.py
def register(registry):
    registry.asset_handlers["my_handler"] = MyHandler()

class MyHandler:
    name = "my_handler"
    asset_types = ["Custom.Assets.MyAsset"]

    def export(self, asset, output_path):
        output_path.write_text(str(asset))

Pip-installable plugins — Use entry points in pyproject.toml:

[project.entry-points."murder_unpack.asset_handlers"]
my_handler = "my_plugin:MyHandler"

[project.entry-points."murder_unpack.commands"]
my_cmd = "my_plugin.cli:my_command"

Available extension points: asset_handlers, extractors, commands, hooks (pre_extract, post_extract, pre_recover, post_recover)

Limitations

C# Source Recovery

• Managed single-file bundles — Full source recovery via bundled decompile-helper (per-type decompilation with timeouts). Falls back to ilspycmd, then to stub generation.
• NativeAOT binaries — Cannot be decompiled. Recovery generates C# stubs for compilation but without behavior.

With full decompilation, the recovery uses the decompiled game class directly and applies targeted compatibility fixes: init → set on engine types that cause CS8852 errors (detected via trial build), readonly removal on class fields for JSON deserialization, and JsonStringEnumConverter for string-based enum keys.

Engine Version Detection

For known games, the fix registry provides the exact engine commit. For unknown games, fingerprint detection covers rel/3.6 through rel/11.0 (some ranges are indistinguishable, e.g. rel/8.0-10.0 default to rel/10.0). Use --engine-version to override with a branch, tag, or commit hash.

Dialogue Reconstruction

.gum script reconstruction from compiled dialogue graphs is best-effort. Semantic content is preserved; original formatting may differ.

Development

git clone https://github.com/yuna0x0/murder-unpack.git
cd murder-unpack
uv sync

AI Disclosure

AI was used to assist in the creation of some of this tool's base code.

License

MIT - yuna0x0